All air gun work and no play not good
LOL Ray

I,ve been meaning to get ahold of you.I tested out a couple of your seals in Warrens gun the other night.First off ,Nice job!The specs I gave you on the outer dia.could be just slightly larger.It fits nice but the factory seal fits in just a little more snug.I,ll try to get you a better reading.The softer sets seem to work fine by themselves but if you install a spacer behind them I believe the presure gets under the breech seal and it gives a burp like feeling to the shot cycle and lower fps.I think we could go a little thicker than factory specs so a better seal would be felt when the action is closed.I also think the harder substance would be the best matierial for the job.
Warrens gun is working out well but I,m only getting 750fps from the JM GRT spring kit.His gun fires at 835fps with the factory spring.It,s smoother with the JM spring but I,m not sure a magnum rifle should be about smoothness or killer fps?Yeah, I,m driving myself crazy with it!

"Warrens gun is working out well but I'm only getting 750fps from the JM GRT spring kit.His gun fires at 835fps with the factory spring."

Thanks John, you just talked me right out of ordering one which I was going to do next week!!! Maybe I'll just get a seal and some lubes. I'm getting about 820 fps with Premiers at 5700 feet and 40 degrees.

Duncan

The Jm spring takes away the harsh firing cycle and is easier to cock but lost 80fps.A rifle shooting at 750fps still delivers a pretty good smack and is still a magnum,but I think I,ll be leaveing my stock spring in mine.

John i made anouther set of four with next step harder in mat. and increased od.015. will send them to you.
Ray

John you should not need a shim with these, if you do it wont need to be .031 thick.
Take care Ray

I,ll have to try them out in my rifle because Warrens is getting shipped back to him tomorrow.I tore it down one more time this morning and polished the whole cocking slide area.Just sounded to gritty when you cocked it.Might have to tear mine down again and do the same thing when I,m bored.